Motor-controlling device.



v No, 895,012.

\ PATE'B i 15) AUG. &, 1998;

HALLOCK. 1 MOTOR CONTROLLING DEVICE. .xrrucnipir gum) NOV. 8, 1907.

w'nmssesQ zz-hy (0441 g. adwgu No] 895,012. PATENTED AUG. 4, 1908.

' F. D.-HALI;OCK. I

MOTOR CONTROLLING DEVICE.

2 SHEETS-431113! 2.

APPLICATION FILED NOV. 8, 1907.

WITNESSES:

ATbNEY l i 1 l UMTED STATES PATENT mm;

FLETCHER D. maroon, or \YILKIXSBLRE, PExxsYLn- 'xis, ASS-IGXOR '1( '1. H. GIVEN, H. A. STEWART, AND E. M. mean. or PITTSBURG, PENfS'iTtifihtsliEClilvl-lRS or wiserlXGHOUSF) ELECTRIC & MANUFACTURING COMPANY, OF E 151 PlTTSBl'RG, lENNSYLe VAN IA. A CORPORATION OF PENNSYLVANIA.

MOTOR-CONTROLLING DEVICE,

A Specification of Lette Application file November 8, 1907, Serial No. 401,311.

rs Patent.

" Patented Aug. 4, 1908.

To all whom it may concem: I

Be itknown that I, FLETCHER D. I'lALLOCK, a citizen of the United States, and a resident of Vi'ilkinsburg. in the county of Allegheny and State of Pennsylvania, have invented a new and useful Im roveinent in MotonControlling Devices, 0 which the following a' is a face view of a starting rheostat embody ing my invention, the circuit connections being also illustrated therein. Fig. 2 is an enlarged detail view of one of the parts of the device shown in Fig. 1, and Fig. 3 is a dia-' grammatic view illustrating a modification of the invention.

In Fig. 1, a starting rheostat 1 in connection with which the invention is empioyed, is one of the standard and well known forms, and comprises a pivoted switch arm 2, a series'bf stationary contact terminals 3 with which the arm 2 engages, and a resistance member 4 suitable oints oisub-division of which are connccter to'said contact terminals, the said resistance member being included in series with the armature 5 of an electric motor 6 and serving as a starting resistance therefor.

The switch arm 2 is rovided with a removable lug or button 7, in the path of movement of which is interposed a bow-spring 8 that is attached to an insulating supporting 'piece 9, which, in turn. is carried by a pivoted armature 10 for an electro-ma net 11 havfl ing an energizin winding 12, the armature 10 being normally maintained in the position shown by means of a s ring 13. One terminal of the magnet winding 12 is connected toa switch member 14 that is carried by the armature 10 and is adapted to engage a stationary switch member 15 to which a terminal v16 of the rheostatis connected. The other terminal of the magnet winding 12 is connected to terminal 17 of the rheosta-t which, in turn, is connected to one terminal I 18 of a rheostat 19 that is included n series circuit with shunt field magnet winding 20 of the motor 6, one terminal of the said winding being also connected to terminal 16 of the starting rheostat.

ierniinals 21 and 22 of the starting rheostat 1 are connected, as usual, to circuit con- '60 ductois 23 and 24 of a suitable supply circuit, and a terminal 25 15 connected, as usual, to a.

terminal of th'e'arinature 5 of the motor 6, the other terminal of the motor being con-- nected to circuitconductor 24.

It will be observed that the magnet winding 12 and the switch comprising members 14 and 15 are included in a circuit in shunt to the field rheostat 19, this circuit being established when the switch arm 2 is moved from left to right in order to effect starting of the motor by removing the resistance 4 from thearmature circuit thereof, the lug 7 thereupon engaging the spring 8 and forcing the switch ineniber14 into engagement with the mem her 15 If switch arm 26 of the field rheostat 19 occupies the position shown in full lines, when the circuit in shunt to the field rheostat is established, a comparatively small amount of current will traverse the magnet windin 12, and an insufiicicnt de reeof attraction will therefore be exerted y the magnet core 11 to maintain the armature 10 in its attracted position and the switchniembeis 14 and 15 in engagement after the lug 7 upon the switch arm 2 has moved out of engagement with the spring 8. The switch members 14 and 15 will, therefore,

be separated, and regulation of the amount of resistance in the circuit of the shunt field ma net winding 20' may be effected in the usua 1nanner by moving the rheostat arm 26 in a clockw se direction. If, however, the position of the rheostat arm 26.

is such that. the resistance of the magnet winding 12 is materially less. than lthat' included in circuit with the shunt field magnet winding .20, as, for example, that indi cated by broken lines, a relatively large 1 00 the and thereby permit movement of. the said "the spring 13 will overcome the force of atbcr (if the switch becomes disengaged from the sprin 8,! whereby the switch members 14 and 15; will be maintained in engagement. Theg field rheostat 19 is thereby shunted, andi adjustment of the field strength of the motor cannot then be effected by further movement of the 'rlieostatarm 26 in a clockwise direction, unless and until the isaid arm is first returned in a.countcrclockwise direction to a position such that resistance of the. magnet winding 12; inav not be greatly in excess of the i'esistance introduced in the shunt field circuit by the rheostat 19. ..Under such conditions,

traction exerted by the magnet ll upon the armature 10, and the switch members 14 and 15 will thereupon become disengaged. Adjustment of the amount of resistance in the shunt field circuit may then be effected as usual, by movement of the rheostat arm 26 in a clockwise direction.

In Fi l, the switch governing the. shunt to the held resistance is operated directly by movement of the switch arm 2, but in the arrangement shown diagrammatically in Fig. 3, it is necessary to manually close aswitch 28 by means of a handle 29 in order that a hook 30 carried by the movable mem- 28 may be disengaged from a post 31 carried by a switch arm 32 switch arm from left to right for the pur-' pose of removing resistanceirom the arma-, ture circuit. It will be understood that the switch 28 will remain closed so long as the resistanceintroduced in the circuit by the field rhcostat 33 materially exceeds the resistance of the retaining magnet-winding 34 for the said switch 28 and that the operation of the system of Fig. 3 is otherwise substantially like that of Fig. 1.

it 'will be understood that structural details may be varied otherwise than as specifically indicated without departing from my invention;

I'claiin as my invention:

1. The combination with an electric motor,

a resistance in the armature circuit thereof, and means for removing the said resistance from circuit, of a resistance for the field circuit of the motor, and means for establishing a circuit in shunt to said field resistance upon removal of resistance from the armature cirwit, and for maintaining the said shuntcircuit while the field resistance exceeds a pre determined value.

2. The combination with an electric motor, I

a resistance in the armature circuit thereof, and a switch arm for removing the said resistance from circuit, a resistance for the field circuit of the motor, a switch operated by the said switch arm to establish a circuit in shunt to the field resistance, and an electro-magnet winding in the shunt circuit for maintaininga resistance in the armature circuit thereof, f

and a switch arm for removing the said resistance from circuit, a resistance for the held circuit of the motor, a switch opera-ted by the said switch arm'to establish a circuit in shunt to the field resistance, and an electro-magnet winding in the shunt 'eircuit formaintaining the switch in closed position while the field resistance excccdsthat of the shunt circuit by a )redeterinincd amount. a

4. he combination with an'electric. motor, a resistance in the armature circuit thereof, and means for rcmovin said resistance from circuit, of a resistance For the field circuit of the motor, a switch for establishing a circuit in shunt to the field resistance upon removal of resistance from the armature circuit, and means for maintaining the switch in closed position while the fieldlr'esistance exceeds a predetermined value.' t.

5. The combination with an electricmctor,

a resistance in the armature circuit'thereof,

and means for removin said resistance from circuit, of a resistance or the field circuit of the motor, a switch for es'tablishing'a circuit in shunt to the field resistance upon the re moval of resistance'from the armature circuit, and an electromagnet in the shunt circuit for maintaining the switch'in closed position while the field resistance exceeds a pred'eterniined'value: v 6. The combination w th an electric motor,

a resistance in the armature eircuit thereof,

and a switch arm for removing the said resistance from circuit, of a resistance for the field circuit of the motor," a switch for establishing a circuitinshunt to the field rcsistance, means for preventing movement of the iris switch arm to remove resistance from the armature circuit except by first closingthe said switch, and means for maintaining the" switch in closed position while the field resistance exceeds a predetermined value.

7. The combination with an electric motor,

liO'

a resistance in the armature circuit thereof,

and means for removing the said resistance from the circuit, of a resistance for the field circuit of the motor, means for preventing removal of resistance from the armature cir-- cuit except by first establishing a circuit in shunt to the field. resistance, and means for maintaining the shunt to the field resistance while the said resistance exceeds a predetermined value. p

In testimony whereof, I have hereunto subscribed my name this 31st day of Oct., 1907. 

